Co2 burner putting off smell?

I pulled an old Blue Ox 8 light co2 burner/generator out of storage. It's been there for almost a decade. Cleaned it up, removed the jets and cleaned them, fired it up and thing works perfectly... nice blue flame, zero delays to ignite.

Only issue is it puts off slight smell, barely noticeable. It's not the smell of propane and I've checked for leaks in the lines and can't find any. If it was the smell of propane it would smell like rotten eggs right. I've been running bottled tanks for years so forgot if I am to expect a slight smell.

It's difficult to explain what it smells like. First instinct would say propane, if you didn't know what propane smells like lol.

Those with co2 burners, does yours put out a very faint smell when igniters are firing?

Never mind, found a leak lol. I decided to give it a second round of leak detection spray. I found very small micro bubbles where the hose meets the regulator, on the underside. I wiped down the area and reapplied a few times and the micro bubbles kept appearing. I've taken the joint apart. Reapplied the tread tape and no more leak. I don't smell what I was smelling anymore.

Odd thing is, what I was smelling did not smell like rotten eggs at all. I mean it smelt "off" but no where close to rotten egg smell.